A mobile user, especially a business mobile user, has often the need to use various services, in particular communications services, through distinct office electronic apparatuses while he is on a travel or simply out of his office.
At present, he needs various different subscriptions (even with the same service provider) in order to be able to use and pay the same or similar services through distinct electronic apparatuses, such as personal computers, typically in different places, e.g. in different countries.
This is cumbersome both as it requires a number of subscriptions and as it requires a number of bills to be issued and paid.
From patent application EP1607906, there is known a couple of authentication cards. A first authentication card is inserted (installed) into a cellular phone and a second authentication card is inserted (installed) into a PDA. The first authentication card comprises an identification code transmission unit and the second authentication card comprises a usage restriction cancellation unit. The two units exchange the identification code by means of wireless signal and authenticate the identification code mutually. In case that the PDA is moved more than a predetermined distance from the cellular phone and the reception level of signal from the transmission unit received by the cancellation unit is smaller than a predetermined value (no reliable authentication may be carried out), or in case that the cancellation unit can not authenticate the identification code of the transmission unit, the cancellation unit stops transmission of the usage restriction cancellation signal to the PDA; as a result, the PDA is no longer in a usable state and the user is no longer able to use it.
From patent application WO0131877, there is known a method and arrangement wherein any private or secret information that is necessary for client authentication can be stored in a specific personal SIM card and used in combination with a mobile telephone as a security gateway to a protected intranet. An employee staying away from his ordinary office may, by means of a mobile phone functioning as a security gateway, communicate with the protected intranet of his employer; the employee can use any remote host in order to access the protected intranet but through a mobile phone provided with the specific personal SIM card. The solution is to move the security function to a mobile telephone where a lightweight security gateway or firewall is implemented. Alternatively, the employee may fit the specific personal SIM card directly into any remote host for communicating with the protected intranet.
From patent application WO9959360, there is known an arrangement for a wireless communication system; this arrangement comprises a wireless communication terminal and a subscriber identity unit which is adapted to comprise a subscriber identity module to which a subscriber identity is assigned; the subscriber identity unit is arranged to communicate the subscriber identity module related data such as the subscriber identity with the terminal over a local wireless communication link; this arrangement makes it possible to separate the subscriber identity unit from the terminal even while the terminal is communicating in the wireless system; the subscriber identity unit may get control of one or more wireless communication terminals and is used for giving authentication to the terminals.